AMG’s hybrid 2+2 leverages a stupefying amount of technology to defy the laws of physics.
In the days leading up to my seat time in the GT63 S E Performance – AMG’s hybridized riff on the recently reinvented two-door GT – I found myself pondering exactly what this car’s primary intent is. While the original Mercedes-AMG GT was a rear-wheel drive two-seater that was expressly designed to go up against the 911s and Corvettes of the sportscar world, much like the SLS AMG before it, the second-generation GT is a different animal.
Now underpinned by a platform shared with the SL, the GT has gained a rear seat, a longer wheelbase, all-wheel drive (aside from the base GT 43 model, which remains rear-drive), and more than a few pounds of heft in the process. While the first-generation GT S coupe weighed in at around 3,600 pounds, its contemporary equivalent (the non-hybrid Mercedes-AMG GT 63) tips the scales at over 4,300 lbs., and this E Performance model brings roughly 500 pounds more to the mix, largely due to the addition of an electric motor and a 6.1 kWh battery pack.
Could a vehicle that’s nearly 5,000 pounds somehow still be considered a sportscar? And if not, then what is it? Even after a week with the car, I’m still not quite certain, but what I can say for sure is this: It looks great, it’s stunningly complex, and it’s fast as hell.
Truth be told, the Mercedes-AMG GT63 S E Performance is ultimately a capable and decidedly performance-oriented luxury grand tourer in the vein of the Aston Martin DB12 and the 992 Porsche 911 Turbo S, yet it out-muscles both of those machines while undercutting them on price.
Under the hood is AMG’s venerable 4.0-liter twin-turbocharged V8, here tuned to deliver a healthy 603 horsepower and 627 lb-ft all on its own. The engine is also supplemented by the aforementioned electric motor, which produces 201 hp and 236 lb-ft of torque, resulting in an official combined system total of 805 horsepower and a jaw-dropping 1,047 pound-feet of torque.
If that math has you scratching your head, you’re not the only one. Mercedes says that rather than simply combining the peak output numbers of the engine and the hybrid system to get the output total, it should be considered as one whole powertrain, and that requires a calculation which would cause Isaac Newton’s eyes to glaze over. The basic premise is that this formula takes the gearing of the car’s two transmissions into account (the conventional nine-speed automatic and the hybrid system’s own two-speed gearbox) to determine accurate figures “at the crank.”
I won’t bore you with the specifics here, but suffice to say this powertrain is a complicated piece of technology. It also makes the GT63 S E Performance the most powerful series production model in AMG’s lineup alongside its drop-top stablemate, the SL63 S E Performance, which is outfitted with the same powertrain hardware.
As with other performance-focused hybrids like the BMW M5 and the Lamborghini Revuelto, a press of the engine start/stop button gets things underway purely on electricity, giving the GT63 S E Performance an element of stealth that your neighbors will likely appreciate on early morning treks out. Although the hybrid system’s battery pack only offers about eight miles of electric range, the car’s sportier drive modes will top off the battery as you drive, so owners will rarely need to bother plugging into a charger.
Unfortunately, the rear-mounted hybrid system does create a sizable hump in the car’s storage compartment, in turn reducing cargo capacity from the 11.3 cu ft found in other GT models to just 7.3 cubic feet.
The GT63 S E Performance offers eight drive modes in total – Electric, Battery Hold, Comfort, Slippery, Sport, Sport+, Race, and Individual. Comfort is the default setting when the car is started, and while the hybrid system can bring the car up to highway speeds entirely under electric power, the V8 is automatically awakened if you’re faced with a steep hill or need more punch than the electric motor can provide.
The transition from purely electric power to a combination of electric and internal combustion propulsion is admirably seamless from behind the wheel, though; on more than one occasion, I had to glance at the tachometer to verify whether or not the V8 had kicked in. For this, I blame the absolutely killer Burmester “3D Surround Sound” audio system!
Despite the car’s performance-focused tuning, poundage, and this tester’s optional 21-inch wheels, it’s also remarkably compliant on the highway and not especially harsh around town when left in one of its more relaxed drive modes. Much of the credit for this feat must be awarded to AMG’s Active Ride Control suspension, which is standard equipment on the GT63 S E Performance.
It features an active hydraulic system that replaces conventional sway bars and assists the car’s adaptive dampers individually during both the compression and rebound movements of the suspension. This pays dividends in everyday driving comfort while also helping to maintain proper camber in the corners during more spirited drives.
Speaking of spirited drives, the cognitive dissonance only got stronger when I ventured out to the canyons. While the car’s substantial mass makes itself known under braking and when quickly changing direction, the suspension does an impressive job of corralling body motion. There’s also a surprising amount of mechanical grip on tap, and the all-wheel drive system allows for plenty of tail-out antics if you’re feeling brave enough to dial back some of the electronic assistance.
Mercedes claims an official 0-60 mph sprint of 2.7 seconds, making this the quickest AMG road car produced to date. I see no reason to refute that claim, but outside the context of drag launches, the GT63 S E Performance does seem like it would benefit from some additional dynamic refinement.
It takes a noticeable beat after a stab of the loud pedal for all of the various systems to get on the same page to deliver maximum thrust, and by the time they’re all on full attack, you’re often back on the brakes for the next corner. And while the transmission programming in Race mode is appropriately aggressive, the gearbox tends to be a bit lazy about responding to downshift requests from the paddle. Pedal feel under hard braking was also oddly inconsistent, regardless of the drive mode or regen setting that was selected, which is a bit disconcerting in a car that’s this heavy and this quick.
Despite its quirks, there’s no question that the GT63 S E Performance is thrilling to drive when the going gets fast and highly competent when pressed into service as a grand tourer. Whether or not it’s a true sports car remains up for debate, but most owners probably won’t be too concerned about that when they pull up next to a McLaren Artura at a stoplight with an air of confidence.
Images: Bradley Iger
